Machine tool



Sept 18 1951 o. E. STAPLES 2,568,667

MACHINE TooL Array/ve ys O. E. STAPLES MACHINE TOOL Sept. 18, 1951 '7 Sheets-Sheet 2 Filed April 8, 1950 INVENTOR. 07/5 .9M/afs SePt- 18, 1951 o. E. STAPLES 2,568,667

MACHINE TooL Filed April 8, 1950 '7 Sheets-Sheet 3 i s Q) k LQ IN V EN TOR.

077s E. hPa-5 rrok/vsys Sepp 18, 1951 o. E. STAPLES MACHINE TOOL 7 Sheets-Sheet 4 Filed April 8, 1950 IN V EN TOR. 027s 574,055

llIlllIl sept. la., 1951 O. E. STAPLES MACHINE TOOL Filed April 8, 1950 y A,wa

I sheetssheet 5 INVENToR. 077s .5r/:P455

,4free/Veys Sept.18, 1951 o. E. STAPLES MACHINE TOOL "Filed April 8, 195o 'fr'4 Sheets-Sheet 7 2 3 4 www T||1|||||| J 4 i ,IITIIIIIIII mw m 1T L ,T l. m. N d 7,. IIT 1| 12 nu u 71. Dimm Y 15G. 75 INVENToR.

077s E'. .S7-Ames Patented Sept. 18, 1951 MACHINE TOOL ons E. staples, Euclid, ohio, assignor to The Cleveland Hobbing Machine Company, Euclid, Ohio, a corporation of Ohio Application April 8, 1950, Serial No. 154,800

23 Claims. k(Cl. 90-4) The present invention relates to machine tools land, more particularly, to gear cutting or hobbing machines of the rotating turret type.

. 'An object of the invention is the provision of jan improved multi-unit, rotatable' turret type machine tool having a single power operated mechanism for eifecting rapid traverse movement in each of the operational units carried by the turret thereby resulting in a less expensive 'construction than prior art machines employing lseparate power means for each unit while retain- "Yingv the desirable operational features thereof.

Another object of the invemion is the provision of an improved machine tool comprising a plu- `rality of operational units mounted upon a rotatable turret, each unit comprising rotatable 'tool and work spindles having rela.ive movement vwith respect to each other in a path substantial- "'ly parallel with the axis ofthe turret at either a rapid traverse or a feeding rate of speed, there Ybeing a single power means for sequentially effecting the rapid traverse movement for each Vunit when positioned at a common loading station.

yA more specific object of the invention is the provision of anY improved machine tool comprising a plurali Ly of operational units mounted upon a rotatable turret, each unit comprising rotatmeans for sequentially feeding movement of each unit either during rotation of lthe turret or while the turret remains stationary.

AA further object of the invention is `the provision'of an improved machine tool as defined in the preceding paragraph and further comprising Enovel ycontrol means for automatically terminating rotation of the turret as each operational unit arrives at the loading station thereby automatically sequentially positioning each unit for cooperative engagement with the single power means for eiecting the rapid traverse movement.

An additional object of the invention is the provision of an improved machine tool as defined in the two preceding paragraphs and in which means are Vprovided for eithermanual or auto- .matic control thereof.

The invention further resides 1n certain novel features of construction and combination and arrangement of Iparts, and further objects and advantages will be apparent to those skilled in the art to which the invention pertains from the following description of the present preferred embodiment thereof described with respect to the accompanying drawings in which similar reference characters represent corresponding parts inthe several views and in which:

Fig. 1 is a perspective view of a rotatable turret type hobbing machine embodying the present preferred form of Vthe invention, Yportions of the skirt or apron for the machine being ybroke-n away and certain parts being omitted for clarity of illustration;

Figs. 2A and 2B taken together constitute a fragmentary vertical sectional View through the machine shown in Fig. 1, substantially atrthe loading station thereof, with .parts in elevation and with the tool or hobhead of the illustrated operational unit turned 'to a horizontal position to facilitate illustration;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2B illustrating one of the units positioned for cooperation with the novel rapid traverse drive;

Fig. 4 is an enlarged fragmentary, sectional View taken on the line 4--4 of Fig. 3;

Fig. 5 is an enlarged fragmentary sectional view taken on the line 5-5 of Fig. 3;

Fig. 6 is an enlarged fragmentary side elevationalview of a portion of the structurefshown in Fig. 3 as seen from the right-hand side of that gure;

Fig. '7 is a sectional view taken substantially on the section line y'l--T of Fig. 2B; Y l

Y Fig. 8 is a fragmentary horizontal sectional view through a portion of the base of the machine showing the turret rotating means; A

Fig. 9v is a sectional view through the bottom ofthe vworkhead of one oi the operational umts of the machine positioned at the loading station,

the machine being shown in top elevation;

Fig. 10 is a fragmentary front elevational view rof the portion of the workhead shown in Fig.*9 jillustrating the positions of the switch actuators;

Fig. 11 is a 'fragmentary rear elevational view `of the portion of the apron or skirt'of the machine at the loading station, the view being taken `from within the apron or skirt as indicatedfby theline lI-II ofFig.9; n

' Fig. 12 is a simplified schematic wiring diagram of the controlsfor the machine; and;

Fig. 13 is a key to the wiring diagram show n in Fig. 12, the key being so arranged that when Figs. 12 and 13 are yplaced side by side the relay coils and contacts in the key are horizontally aligned with the corresponding coils and contacts in the circuit diagram, the contacts actuated by each of the relay coils being vertically arranged in the key above or below the vproper operating coil.

The invention is illustrated as embodied in a rotatable turret type hobbing machine similar to that illustrated in U. S. Patent 2,292,260, issued August 4, 1942, to Adams et al., and to the 'machine illustrated in my copending application S. N. 757,256, filed June 26,1947, and hence only those parts of the machine are here illustrated and described which are considerednecessary to convey a complete understanding'o'f'the'invention to those skilled in the art.

The general nature ofthe machine will be ap- ;parent from an inspection .of Figs. l, 2A.and 2B, vfrom which it will be seen that the machine is lsupportedbya stationary frame -A on which a vided with'mechanism for supporting and rotat- .'I

.ing a hob or other tool, the tool being Aadapted .to be rotated about an axisextending transversely of the vertical movement ofthe .adjacent work- V.head and preferably each hobhead includes mechanism for producing a relatively slow axial i movement of the hob or othertoolwhile the latter is rotating. VEach workhead includes, a .means E-.for supporting .and rotating a workpiece about a substantially vertical axis and mechanism F for producing a feeding movement of the vWorkhead vertically during a cutting or hobbing operation. This rotation of the workpiece and `feeding movement thereof Vis in timed relationship to the rotation of thehob or other tool, as Will be readily apparent and hereinafter described. VThe machine also includes, in accordance with thisinvention, a single rapid traverse mechanism GforA moving eachV workhea'dat a rapid raterwhen the corresponding operational unit is positioned at theloadingstation to' there- A, by bring the work into Acutting relationship "with A'the hob'or'other tool and "toY return Ytheeworlrhead to its initial position after the cutting op- Aeration has been completed.

In operating the machine, thelturretB fthereof isfrotated so that the operational unitsfthereon successively pass andefinite position .known as the loadingstation Where .the workpiecesare ,inserted .and removed and .rapid .traversemove- VV:ment ofthe workheads effected; The. hobloingf or :other machining operation isA effected, during normaloperation of the machine, asthe-turret rotates, the cutting or hobbing operation being normally completed by the time-a given workhead :has returned to the loading station. The manner Yin which the various operations are eifected and I vcontrolled will hereinafter become apparent from V-andpbase.bysuitable bearingssuch, as 22, 23and v 24. Rotation of the turret B is effected by means Y of a motor l25 (see Fig. 8) which operates through suitable reduction gearing 26 to rotate a worm 27, the shaft connecting the motor with the reduction gearing preferably being provided with a spring engaged, electrically released brake 28 member 30 is secured by bolts or other suitable means to the lower part of a vertically extending annular member 3l forming the main frame of the turret.B.

Each of the toolheads C comprises a tool or hob spindle 32'` rotatably supported upon a spindle member 33 which is in turn carried by a slid- *able headmember 34. Each spindle member 33 is angularly adjustable relative toits head member 34 about an axis normal to the axis of the `hob or toolspindle 32 and is .secured tothehead member 34 in any adjusted .position by bolts 35A, the heads of which engage withinarcuate'T- shaped openings-35B in the frontfface of'fthe member 34. The head members34 aref'slidably supported upon horizontal ways 36 on ythe. annular portion 3i of the turret and the head members are adjustable therealong radially rof fthe axis about which the turret rotates. This adjustment is-eiectedby 'means of screws 3.7, each f which engages a threaded member .ornut 38 .connected withA the lower Vportion of the toolhea'd 34. Thescrews'i are each -J'ournalledin a portion of the turret annular-member'-3l for rotation without axial movement. Consequently, .when 4a screw 37 isv turned the .corresponding slidable head member 34 moves radially, .the extent -of .movement being indicated by' meanslof .a.dial39 carried by the-screw and cooperating Withfa stationary Vmarl: upon the turret.

Each of theV-workheads `D is preferably .provided with a suitable VWork holding androtatingfmeans E. This comprises .a-work, spindle 40 Whichgis rotatably supported in the lower portion 4| ofthe workhead by ,suitable antifriction .bearings such pas 42-and 113. The upperendofeach spindleis preferablyprovidedwithV a chuck, not shoWn,.ad each of the workheads is further provided with a tailslide Ai4 which Vis slidablysupported upon suitable ways on the vertical portion yof `the workhead D. TheV slide d4 may 4be moved .-'to .an adjusted positionand --heldthereinby suitable mechanism comprising rack 46 and -a handlel foroperating-a pinion,.not shown, but which-cooperates With thefrack 46 as will be fully understood from` the.-abovementioned patent andmy copending applications. N. 757.256. Eaohofgthe tail slides Vt4 iswprovided withY a. tail.center.48 for engaging the work held on the workspindle 40. T-he workhead members D-are slidably supported on verticalways mand Bil-provided on `the annularmemberl and acaplmember 5!respectivelypsaid cap member being -integral with,

or secured to, the top-of .thez annular ymemberl so as to form abortion of .the turret. Movement of the Y'workhead D along-the ways-491 and-Sons effected by mechanismhereinafter described.

to a shaft ,.54 througha ilexiblefdrive' 55, the shaft 54 being journalledfin a .stationary portion of the housing connected vwiththe columnfZl "The nular member.

iime'r end of the shaft I51| Yisprovided with a bevel gear v 56 meshingwith a ring-shaped bevel gear 51 connected to the upper end of a rotatable sleeve 58, the latter being rotatably supported by bearings 59 and 80 upon thercolumn 2|. The

lower end of the sleeve 58 has a ring-shaped bevel gear 6| attachedfthereto which meshes with and drives a plurality of spaced bevel pinions 62, there being one such bevel pinion 62 for each operational unit mounted upon the turret.. Each pinion 62 is keyed to a short shaft 63,'rotatably supported by bearings such as 64, 65 in the rear portion 66 of a two-part housing attached to the member 3| and cap portion 5| of the turret B adjacent the edges of an opening therethrough. 1

The driving connections to the various operational units from the gear 6|, through the vgears 62 and shafts 63, are duplicates and therefore only one willbe described in detail.

wardly and rearwardly therebeyond, rthis shaft being selectively operatively connected with the shaft 63 by means of a friction plate clutch 1|. This clutch is of conventional design and comprises a driving member 12 connected to the shaft 63 and a driven member 13 connected to the shaft V1|). The cooperatingfaces of the members 12,

13 are supplied with friction material 14, 15 respectively and are normally forced into engagement by a plurality of spaced compressioncoil springs 16 exerting force between the rear of the driven member 13 and a housing member 11. The rear face of the driven member 13 is provided with a plurality of integral bosses, only one of which is shown, in each of which is 'mounted an axially extending rod 18. Pivoted to each rod 18 is a radially extending actuating lever 19 which is urged to the illustrated position by the springs Y16 since the lower portion of each lever engages a cam surfaceY in a recess providedin each of the integral bosses on the rear of the driven member. This action may be assisted, if desired, by providing each lever 19 with an auxiliary spring, not shown. The upper portions of the levers 19 extend adjacent the shaft 10 and are adapted to be rocked by an annular member 80 which is rotatably and slidably supported upon the sleeve 69, the annular member 80 havinga Y,

circumferentially extending groove or recess 'thereabout engaged by shoes in the lower ends of a bifurcated lever 8| straddling thesaid an- The lever 8| is pivoted intermediate its ends to the forward portion'61 of the two-part housing, the lever extending vthrough an opening in this housing.

The upper end of the lever 8| is pivotally connected to a rod 82 which has a threaded conpending lug or bracket 84.. The lever 8| is adapted to be moved in a clockwise direction as viewed in Fig. 2A by the application of fluid pressure to the rear of the cylinder 83 Athrough a 'exible pipe or hose 85, thebforwardportion of the cylinder' being provided with an exhaust This portionof the housing port', not shown, communicating the aa irl fr'iit 'of-the piston with the atmosphere.

' The Vflow of uid under pressure to the cylinder 83 'is controlled by a two-way valve 86 (see Fig. 1)V mounted upon the cap member 5| of the turret. The previously mentioned hose 85 is conlnected to this valve 86 which is also provided with a fluid pressure supplying pipe or hose 81. The pipe 81 is connected with a spider, not shown, which is rotatable with the turret relative to a stationary pipe |49 connected to a source of supply of fluid under pressure. The valve 86 has an exhaust port preferably provided with an ad- 'justable orice controlled by a needle valve or the like, not shown, which is more fully disclosed in the previously mentioned copending application S. N. 757,256. The movable member of the valve 86 is connected by an actuating member or rod to the armature of a solenoid or electromagnet 88, the valve 86 being so formed that when hoses 81 and 85 and to establish communication between the pipe or hose 85 and the exhaust port of the valve 86. Hence, the springs 16 of the clutch 1| now act through the driven member 13 upon the levers 19 and the annular member 80 to rock the lever 8| in a counterclockwise direction. This moves the piston vof the cylinder 83 to the left, as viewed in Fig. 2A, thus discharging the iiuid in the cylinder through the pipe or hose 85, valve 86, and the exhaust port of the latter. The provision of an adjustable orifice for the valve 86 controls the rate of discharge of the fluid and hence the .rate of engagement of the driven member 13 of the clutch kwith the driving member 12 under the action of the springs 16, thus preventing grabbing. The clutch of each operational unit is similarly constructed and controlled and the manner in which the solenoids 88 are energized and deenergzed during the working cycle of the machine to effect "operation of the clutches will be described hereinafter.

A bevel 89, provided with an integral sleeve 90, is keyed to the shaft 10 intermediate the ends of the latter. The sleeve 90 is journallecl by bearings 9| in the shoulder or flange 68 of the forward portion 61 of the two-part housing, the sleeve 90 and hence the gear 89 being held against axial displacement by a nut 92 threaded upon the outer end of the sleeve and engaging the adjacent face of the inner race for the bearings 9|. The outer end of the shaft 10 is splined and provided with a bevel gear 93 which is ,slidably keyed to the splined portion of the shaft. The gear 93 is provided with an integral sleeve portion rotatably supported in a member 94 by bearings 95. The member 94 is connected with the spindle supporting member V33 and the sleeve of the gear 93 is held from axial displacement with respect thereto by means of a nut 86 provided upon the threaded outer 'end of the sleeve.

' The bevel gear y89 meshes with a bevel gear .fee ng. the fworgkgspindle .f `and for.,rotat ng and axially ymoving y the s. tool vspindlef-respectiv ely. Gonversely, A. disengagement ofL ,the clutch .--1 vinterrupts rotation of. thegshaft .'i-. simultaneously ,.stoppingfthegmechanisms driventhereby.

.38. i is splineclandL passes through `a y bevel gear 45021. keyedto the fsplipedportionpf .the shaft ,38. and rotated .thereby. .,The.-.g.ear .|82 is .1^.o,t at ably Supported-.within a. housing forming. apar-.t ,of-.the .1o,wer,..portion li! offthe..vv-orkhead,V .the gear heiligheid.,againstaxial displacement. with .respect--totheshousing- While the splined portion of the shaft 98 permits the workheadto .be-moved relative1.to. the.latter. -Thefgear-.LUZ is in mesh ...WithT-a,-.hevel..gear f||33lprovided onthe end ,ofa .horizontally extending shaft. |534.. rotatably jour.- nalled,.in.t he.lower-portion of the Workhead .4| gby. .bea ri ngs such ,as 405, .13.6. The endof `the `.shaft |64, opposite. that provided with. the vgear -103V extends. into d-.a gear -box forming apart .fot the. portions |v ofv theworkhead and provided with..a removable. cover |67. .hoxrare provide d s uitable changey gears 1.08, .for effecting rotation ofthe \vork s1:iindle4 4B, .these gearsQdrivi-nga-.worm itil in mesh With a WorinV whe'ellii .keyed :to the work spindle All. The :.detailslf this drive. can. be readily determined from inspectionoffiig. 'Zand further detailsean be foundhy reference toeither of the Adams etal,` patents, 2,6481173 or 2,292,260.

Ihelovver end of gthework spindleuis projvided t3/tithe. pinion Hi `driving a gear ||2jpro videdupona y s tuo shaft v| i3. The gear |2..is integral with oreonnected. for rotation with va gear list, thelatter being in meshwith a gear |"|,5; keye d, to an elongated screw V| 6. The .Screw 5,.hei`eh.2f-er -called the ee-;l. screw, has its upper end rotatably supported in the lower...part ,of the Workhead by bearings and is held ',.rornaxial displacement with respect thereto by v Ineansof a nut ||8 and an integral shoulder A. cooperating with the bearings and the gear 5, as willi be readily apparent from Fig. 2B. The .Screw H6 is threadably received within a feed nut H9 rotatably supported by bearings |20 in La bracket member. |2| connected with thelower V portion ofthe annular member 3|. The feed nutis provided Witha spur gear |22 keyed therel.to fora, purpose hereinafter described, the gear '|22 and vfeednut. being held against axial dis- ,placement .relative to the bracketrl2| by means of a nut 23 th readed upon thelower. portion of the. feed nut' |9. l.It will beapparent from the structure thus ,far-.describedthat rotation of the shaft 98 drives fthe, gears ,|!!2,- H33- thereby causing rotationof L.the .shaft Hidandthe gears, |08 with the latter rotating the worm |09 and wormyvheel H0, so t.that thefwlkqspindle 4.0, and .the Work, sup

Within this .gear

described, heee ...crew Ilthreadne threes.h ltheifeed eau-;fori..letirlethismevement rer. ely.-.-.wh.er1.;the eeerztm .is-freed for rptatioil and hezsheft .isf not' driven, ,-.the werkhead may be ffmeved @vertically Eleylnetatins the .eser

.tiQr1.-Qf.;zthe..feed `m,1t-;KI. 2.can hegel; e reletsly renidirate; for eff-.eating .rapid.ftraversefmgrereeet s thetwerkheadeeeeerelenee :.with'this invention e :nevel mechanism is .pr oyided for Aeffecting ,rapid trave `erse mevemeritof. .the ,workhead throughretetion of-1 the gearf| 2 2 atv the loading .station for th e apperetusehy emnleyieg etsi'nele drive meter selectivelycooperates with eachV of ithe 'hesitertisrnalvunits-Y.-y as-...they are sequentially .pesi adingestation. For this purpose, he-machine is provided with la eetrw arreter. 4.LZfLtlle .ermeturesheit sqrrrretedfwitrrahelisel gear 25,1596

.helielreear f! 2.6 ;1. eyed.11p0n.s.;.1ie11ew spiedleil' preiesirielppwerdly .-threueherr ripening :mills ibase. 2f-:the apparatus et thelgedins .setienadiesent the sears -|2.2..-Ofthe-)Operetienel units- The .spiedle Urisrqtatebly-sepnertea .es brbearriss i 9 .r1 als |30 whichy es shore slml 25.-.fid :is lfxwedetofhe e-.Qfi-rthemeshir1e-. :The upper portion effthe ndle |21 is-splined andhasthe elongatedhub .i3 'fsf .fleysd'tlisreto This eser' {3i-'is .adapted t meshwii-htheA gear., |22 on eaehof .the.. feed nuts -offeach operational unit successively, b ut; isnormallyfhelddisengaged therefrom .Abyfmeans'gof a. .coilfspring |33 .acting betweena seat. in th upperend ofthe spindle |2'Iand. a shoulderoncollar n|34 .provided upona lrod v|35 ,extending through the hollow interiorv ofv the .spindle |21. intermediate Athe collar or shoulder .134 and,.the,. huhzof .the gear |32 is providedan iani-.ifri c tion. :hearing |3 6,the latter being heldin plaee..by adisk member |31. secured to the outer endo-f the. rod .iand having a function herein- ;a fterdescribe.d. rlhe. VlcWerend of the rod |35,is 4 .c. o1 1 r iec.ted to.. a piston` within aV cylinder I 38, the latter. beingr secured to .the lower portion. of the 4.housing v|30 andbeing provided with a uid pressure.inlet port 3 9 and an exhaust port |40. .I teferringnowto'v'Figs. 3 through 6, it'will be oliseryedfthatthe ,bracket |2|, whichsupports Ii', he ,fee d nut. |19 andthe gear |22, has anjupstanding .ear .orjflange i 4 spaced. from a vertical planar portion of the bracket, thereby providing a Ysubstantially rectangular lrecessrtherebetween. .Alever 14.2.35. nii/stellv mqurrted Within .this recess brirreerrspts 'pivot "43 passing throuehihs leverand ,received Within the bracket |2 audits .ear`|4|,. as will loe apparent v from Figs. Sandri. The lever 142. is c ,urved as will be apparent from i g's 3 and andhas its forward end |44,exte nd ing .through a.. s lot .or opening in the bracket '|21 the-loWerendof this .portion |44 Aof the Alever were Qaslnnientioaedgdisk 'lrrvided-Qnthe rod |35 and is adapted'to be engaged by the latter for removal of the-pin |45 from between the teeth of the gear |22.

The construction just described is such that with the parts disposed as shown in Fig. 2B the pin |45 is between two adjacentteeth of the gear |22, thus preventing rotation of the latter and hence of the feed nut ||9. Consequently, when the clutch 1| is engaged the resulting rotation of th feed screw causes vertical movement of the workhead at a relatively slow or feeding rate of movement. Conversely, when the clutch 1| is disengaged so that the feed screw IIB is held stationary through the locking action of the worm |09 and worm wheel ||0, the workhead of a given operational unit may be moved at a relatively rapid rate in a vertical direction hereinafter called the rapid traverse movement through operation of the motor |24 and the fluid pressure cylinder |38. That is to say, the application of lluid pressure to the cylinder |38 through the inlet |39 causes the rod |35 to be moved downwardly compressing the spring |33. This brings the disk |31 into engagement with the rear portion of the lever |42 tilting the said lever and thereby disengaging pin |45 from between the teeth of the gear |22 so that the latter and the feed nut ||9 are now freely rotatable. As the rod |35 continues to move downwardly under action of the cylinder |38, it carries the gear |32 into meshing engagement with the gear |22 of the operational unit then positioned at the loading station. Consequently, when the motor |24 is now energized, the gear |32 rotates gear |22 and feed nut ||9, thereby moving the Workhead in a vertical direction at a relatively rapid rate. This rapid rate of movement is terminated upon deenergization of the motor |24 and termination of the application of fluid pressure to the cylinder |38. `When the fluid pressure is no longer supplied to the cylinder |38, the spring |33 disengages the gear |32 from the gear |22 thereby terminating rotation of the latter and the upward movement of the disk |31 allows the forward end of the lever |42 to again drop to the illustrated position with the pin |45 between the adjacent teeth on the gear |22, thus preventing rotation of the gear |22 and feed nut ||9.

As hereofore mentioned, there is but a single rapid traversing mechanism for all of the opertional units of the machine. This rapid traverse mechanism successively cooperates with each of the operational units as the turret is rotated or indexed with respect to the frame of the machine, the rotation or indexing of the turret being terminated as each operational unit is positioned at the loading statoin -in proper alignment with the rapid traverse mechanism for operation thereby. Control of the indexing or rotation of the machine and the feed or, rapid traverse movements of the workhead are electrically governed by suitable switches as is hereinafter described in detail. The application of fluid pressure to the cylinder'V |38 is also electrically controlled by means of a'solenoid |46 actuating a conventional valve |41 governing the application of fluid pressure from the supply pipe such as |48 connected to the main supply pipe 49. The fvalve |41k is of conventional construction and hence is not illustrated nor described in detail. As mentioned heretofore, the disengagement of the clutch 1| as well as the engagement of the rapid traverseV mechanism yGr are effected by fluid pressure operated mechanism. This mechanism may be either hydraulic or pneumatic in nature and supplied from any suitable source such as a reservoir and pump located in the base of the machine. As shown Yin the drawings, however, air pressure is utilized and supplied to the machine from an outside source of supply, suchk as the air line commonly providedin factories for cleaning purposes or the like. The air under pressure is conducted from such source of supply to the machine at the top thereof through the previously mentioned stationary pipe |49. 'I'he supply pipe or hose |49 is preferably provided with a pressure responsive electrical switch |50 connected in series in the control circuit for the apparatus to thereby prevent operation of the entire apparatus in the event there is a failure of'air pressure, which failure wouldcause improper engagement of the clutch 1| and failure of the rapid traverse mechanism to operate properly.

It has been previously stated that the hob or tool spindle 32 is rotated when the clutch`1| is engaged and in addition to its rotation this spindle is given a slow axial movement to thereby evenly distribute the wear on lthe hobv or 'tool throughout the axial length of the latter. The mechanism for accomplishing this rotation and axial feed of the hob is contained within the housing 5| and is driven by the shaft Illl. This mechanism may be either of the type disclosed in my copending application S. N. 757,256, filed June 26, 1947, or the copending application of Staples et al., S. N. 56,726, led October 27, 1948. In view of the fact that these mechanisms for axially moving the hob are fully disclosed and claimed in the said copending applicationsI and since this feature per se is not a part ofthe present invention,the details thereof need not be described. Suice it to note that the mechanism includes a microswitch, hereinafter referred to in conjunction with the operation of the machine, for preventing the resumption of a new cycle of operation for a given operational unit of the machine when the'hob spindle thereof has been shifted its maximum extent, an indicating light being provided to advise of this fact.

In addition to theabove mentioned features, the machine is also provided with a coolant system for supplying a cutting or cooling liquid to the hobs or tools during a machining or hobbing operation. The coolant or cutting liquid is supplied from a reservoir within the base of the machine by means of a pump connected to a conduit |52 extending upwardly through the column 2| of the machine. The conduit |52 is connected to a pipe |53 which discharges into a trough reservoir in the cap member 5| of rotatable turret (see Fig. 2A).` Equally spaced pipes |55, one for each unit, conduct the coolant or cutting fluid from the trough |54 to nozzle members |56 adjacent the hog or tool spindles of the units. These nozzle members are so directed that the coolant or cutting uid 4will `flow over the hob or other tool and the workbeing cut thereby, the liquid being returned to the base of the machine by gravity for cleaning and further circulation. Intermediate its nozzle |56 and the reservoirY |54, each of the pipes |55 is provided with a valve |51 actuated by a solenoid CS (see Figs. 1 and 12) so that coolant is allowed to flow only when a cutting operation is being performed and is automatically terminated when that operation has been completed. Lubrication for the machine is provided by a circulating system of conventional design, the vertical supply rpipe |58 of atea-cav;

151i which; extends throughthefhollow columna 2 l", see

2A yandZ'B.

' The base- Ziof the,` machinelisprovided with; a vertically extendmgnstandard |59; adjacent'the loading. station, .Lt-he..` latteribeing formed by reducing the height 'of a portion. of .theapron or skirt: |60 surround-ing thebase-.fof themachine. Adjacent the top.: of. thestandard. |591is mounted a switch box |6| pr.ovided:with switches Vfor controlling the rotation or indexing'motor. 25, the cut. rnoto1-;.-52,".therapidi traverse motor: |24, and theimotor |62-forzthe-coo1ant pump |62a. For thisapurpose, the switch box IGI is provided with manuallycperated-.start button |63.and stop buttontzlfdqfor.. the cut :motor 52; start'button |65 andi.' stop button |66ifor the. coolant pump motor |621; 4.start zbutton'. Iiiandstop button v| B for 'the index or .rotation motor 253 startbutton. |59! and stop button 1U for..theirapdftraversefmotor. |24; andi jogqswitche's 254'sand 2.55 -for `.theintlex motor 25. In. addition, :.thef box*4 .I 6 |Vv is provided. with. a two-position, manually.V operated switch adapted to be set fin. either manual or automatic positionand thereby conditionthelmachine for either 'manuaL or automatic control. Adjacent the switch I:`| li-.isprovidedfaisignal light |72 which, when illuminated;:indicatesV that` onev of the op.- erational is properly. positioned at the loadingistationforf effecftingf..loading and unloading of nthe. work and. rapid-itraversefof itsv rworkhead. The. electrical interconnectionsbf .theswitches operated -by vthe pushibuttons just mentioned; and their. cooperatingfcircuits` areischematicallyrepre.- sented in Fig. .12,v Whichgalso.; shows..v a. .schematic representation; of.y the.; electrical; circuits forjone unit of thehobbing machine; The relaysand circuits controlle'duiby.thaswitchestw'to 254 and. 2.55: areaenclosed Ainv-:a main. control Vbox |13 mounted; upon, or. adj acentfto, thestandard |59..

YElectricalpov/.ere` isoconducted; .toi eachv of vthe operationala.unitsirotatingawithithe turret B by collector rings' |.'|.4,"1|'|5f, A|;'|.|5. andv brushes |19, |80, .|8|1.schenmtically.-indicatedinllig.` 12.. The collector.. rings.. |14, -f||5, |;1.61.are preferably .supported i upon. theiuppertportion of. thecolumn 2 upon-'an .insulating mounting |'|'|f secured Ato a bracket orzdependingmember. adjacentz'the rotatingicapfllgof therlturret, see Fig. 2A. A suit.- ablelhousing.. L'lfprovidesa cover rfor the collector rings .and brushes. 'I-'he brushes-conduct .the electricalfpower ffromthe collectorringsVVV I J4, |15, |116 to fseparateelectrical control circuit foreach unit whichuare enclosed inseparat controlcabinets-orfboxes |82. (see Eig. 1), therebeing a separate box. for-.each `unit .supported t0. rotate Withv the turret by suitable standards 4such as |83 extending upwardlyf-romthecap member 5|, see Fig, 2A.

Depending. from 1 each cabinet. 82 as bymeans of; a. suitable electrical conduit orrpipe` |84, is a station. orzunit switch. box liprovidedwith the previously mentioned: indicating light 8.6: associated-with the,hobshiftingmechanism. In addition the unit 'box` |8 5 is alsoy provided' with switchcperators |81, |88n andv |39A for controlling the coolantyalve: andthe startingand stopping therefonseelig. :2A... Thesesswitchesare of the. type which: are spring-urged:v tocircuit'opening. position and each is providedfwitha rocking. arm |92, the. outereendoff whichxhasf.aurollerzV |93 thereoniextendingsinto:the path oiia single sta tionarycamrlS. '.Thiscamfiszmounted on. the outer. .end of. an elongated rodr or bar liipositionedadjacent' the loadingstation for theimaa chineV and. having; inner endl supported: 'upon the. stationary. top of the machine. between :the motorL support 'Eiland-the :hollow spindle 2|? Hence, ias the turret.offfthezmachinebegins to rotatewhen each unit leaves ther loading," station, the correspondinguswitch |91. 'is a operated ym0` mentarily to: closedfposition-.gby.the camuxl; The switchiis returned to open position` as. soon asl the' roller thereof vhas .passed the cam asthe turret continues .torotate On. the outer-surface of the capmemben 5|A of the turret, :adjacent the top portion of.A each workheadD, is providedanel'ectrical switch- |186; Thisswitch is providedlw'ith. a 4rocking arm v|911 havingv a roller ISK-extending in: the pathiofan adjustable abutmentv or-buttonf |199; TheA abutmentior button |99 is .fslidablydisposed Withina slot EBGLeXtending vertically-fof the upperportion offthe .workhe'adfD-,qthey button or abutmentbeing secured-dn any adjusted position therealong. The

switch. v|196 f' is #of *the type.A such.. that it-normally remains in theposition'to whichfit: is actuated by. engagement. off the.. button or.A abutment |99 with; its roller |38; the relationship of `thel parts beingsuch that-.the arm |191 `maymove-suinciently to allow the'buttoncr. abutmentftopassthereby.'- The oppositeside.. of the top ofthe Workhead'is likewise .provided with a slotf| (see Figl) in which .one or more abutmentswor buttons 202 'mayY be.'.adjustably :positioned- 'fori cooperation with .an "overtravel, limit switch.V This# latter switch. is" preferably enclosed within: the: upper part "oft tlfrez;` workhead; Vbeing schematically indicatediat 20.3 inLEig.r.12'." Y

Theportionoffthe skirtorapron A|60 adjacent the loading. station ot the machine'fis provided .oni its inner surfaceWith a plurality ofi electrical switches for cooperation with switch operators carried'. byeachcf the' -operationalunits as the latter. are rotated by theturreti Inthe form shown in the drawings, the switch operators are provided: upon Vthe lowerport-ion of the wWorkheadsfof theoperationalunits and preferably upon. the removable `cover |01. The switches upon 'the .apron are preferably-adjustably mount'- ed thereon andinclude a switch 20d-for terminating energizationrA of the'index or rotation motor 253 as l.the turret is moved tothe loading station. A switch zet-is. positioned adjacentthe switch 204 for conditioningl theunit ofthe apparatus to beginV a machining operation, the switch 20 5 being so positioned` that.v itis contacted and'operatedfonly When. the unit-is properly positioned for "engagement of its 'gear |22 with the gear |32 of the` rapid traverse mechanism. Preferably @aanl of .the switches 204; 295.15 provided with an elongated bar such as 2236,V ZUIQrespectiVeIy, havingguide pinssuch as 208, 20'9' extending through Slots inthe apron-or shield to permit adjustment ofi the switch and actuating bars Whiley at the same tme'preservingrthv; saidfbars inyproper vertical position Thebar .'2'05, 2,61` are adapted to be engaged and `actuated sequentially by a single actuator in the form of a rod or bar 2|0 provided upon the lower portion of the workhead D, see-Figs, 2B, 7, 9 and 1|).

' The apron or skirt |60 is also provided at the mesma leading station with electrica switches 2U and; 2I2 which may be adjustably positioned relative tothe skirt or apron by suitable mounting screws passing through slots 2 I3, 2 4 in the apron as will workhead on the opposite side thereof from the switch actuator 2|0 as shown in Figs. 9 and 10.v

Switch 2|2 is adapted to be actuated by an abutment member or arm 2|6 provided upon thev workhead at a slightly higher elevation than the switch 2| 5 and to one side thereof as is also indicated in Figs. 9 and 10. Intermediate the switches 212 and 204 is provided an additionalA switch 2| 1 adapted to cooperate with and be operated by an actuator or cam 2|8 of relatively large surface provided substantially centrally uponthe lower portion of the workhead D. Switch' 2|1, like the switches 2| I Yand 2I2, is mounted for-vertical adjustment by'means of a slot 2|9 in the skirt or cover |60. The several switch actuators 2|0, 2|5, 2| 6 and 2|8 arealso preferably adjustably mounted on the cover |01 of the workhead. The relationship of the several switches and the actuating arms therefor, when the operational unit is properly positioned at the loading station is indicated in Fig. 9.

Referring now to Fig. 12, it will be seen that power is provided to the power supply lines 220, 22| and 222of the machine from mains L|, L2 and L3 through adisconnect switch 223. The supply lines 220, 22| and 222 are connectible toprovide power for operating the cut motor 52, coolant pump motor |62, the index or rotation motor 25, and the rapid traverse motor |24, ,as hereinafter described. In addition, the wires 220 and 222.are connected to the primary 224 of a transformer 225, the secondary 226 of whichsupplies the current for the control circuits of the apparatus. Thus, one terminal of the secondary 226 -is connected through a fuse 221 to a power supply line 228 while the other terminal of the secondary 226 is connected through a fuse 229 to the power supply line 230 for the control circuit. The wire 228 is connected by a wire 23| to one terminal of the coil of a relay SR, the other ternected to a wire 232 which is in turn connected with one terminal of the switch |50 provided in the air supply pipe |49. The other terminal ofY thisswitch is connected by a wire 233 to one terminal of the normally closed contacts SRI of relay SR, the other terminal of these contacts being connected to a wire 234 between whichV and the wire 230 are connected the several switches and relays for controlling operation of thev apparatus.

The wire 234 is connected to the collector ring |15 vand the Wire 230 is connected to the collector ring |16, while wire 23| is, as previously mentioned, connected to the collector ring |14. The brushes |19, |80 and cooperating with the collector rings |14, |15 and |16 are connected'toY the control circuits for the separate operational units through the wires 235, 236 and 231, respectively. Since the circuits for the several units are identical only one is illustrated in Fig. .12. y

The connections of the several switches and re-` lays comprising the control circuit for the apparatus and which are connected with the previously mentioned wires 230, 23|, 234, 235, 23,6, and 231k can best be understood in conjunction with a description of an operatinglcycle of the machine when read in conjunction with Figs. 1'2 andV 13. It should be noted that Fig. 13 comprises a` key for Fig. 12 such that when the two figures are placed side by side in alignment, the relays and contacts in Fig. 12 are in horizontal alignment with the corresponding relays and contacts in Fig. 13 and the contacts associated with and operatedby a given relay coil are in Vertical alignment with each other and with that coil in Fig. 13 being interconnected by broken lines. By keeping Fig. 13 horizontally aligned with Fig. 12 the location in the wiring circuit of any contact or operatingv coil vfor a given relay can be readily determined. ,OPERATION Automatic The machineY of this invention is ordinarily in-` tended to be operated in an automatic manner; that is to say, each operational unit of the machine will automatically eflect a machining operrapid traverse the work into cutting or hobbingV relationship with the tool upon the tool spindle. whereupon the rapid traverse movement is automatically terminated. Thereafter, the workhead is moved at the feeding rate for engagement withr the tool of that unit, the tool and workpiece being supplied with coolant. TheI vertical movement of the workhead also operates a switch to automatically begin indexing or rotation of the turret, thus moving the latter to bring a new operational unit into position at the loading station Where the steps of inserting the workpiece and starting the operational movements are repeated as before, the previously started unit continuing its machining operation whether or not theturret be in rotation or stationary. As each unit returns to the loading station, after a complete revolution of the turret, it will again be automatically positioned for cooperation with the rapid traversing mechanism, the machining operation having been completed before this repositioning so that the feeding mechanism is no longer operating to move the workhead vertically. As the workhead comes to rest at the loading station, momentary actuation of the start switch for the rapid traverse motor returns the workhead to its initial position and a new cycle may then be started. f

Inv initially preparing the machine for operation as above summarized, the operator will initially close the disconnect switch 223 and see thaty air under pressure is being supplied through the conduit or pipe |49, thus closing the switch |50. Moreover, he will see that each of the workheads for each o f the operational units has not been positioned beyond its permissible limitsof travel so-that contact 203cv, of the overtravel switch 203 is closed and contact 20319 of that switch is open. Theoperator will also position the switch |'|I on the main control station |6| to its automatic position and move the toggle switch of each operational unit to its automatic position. As each unit is sequentially brought to the loading station, the operator closes the switch |81 thereof in the circuit of the solenoid CS controlling the coolant Valve, and moves the toggle switch |90 of that unit to its automatic position.

The operator also momentarily depresses start button |63 for thejcut motor 52. Since the switch 2,23l has been previously closed, the transformer 2?' 5 is. .110W -enefgzd thfough PQWePOWing .in the.

' most position;

asesina:

travel: limits, thefrelay SRfisnotrenergizecso thatiV itsscontacts SRI. are-closed.` Moreover;since air-f underfpressuenisf'suppliedf throughlthe *pipe-:149g pressure f responsivev switchn |5|isfis f1closed:y Con-.- sequently, operation'. or the 'switch'zi 63 closes: the:` circuit; from -the r wiref` 2-3 4f. through the normally? closed. stopY switch Grand. thevv `nowclosed start-- switchil 6-3zto andJ through the coil .1of::the:relayV G'Isto the :wire 230i` Thisr energizesth'ewrelay CT" a holding circuit around the start switclial':

so that the relay CIlvremainstenergized when the switch |63 is released. Closing the contacts CT2, CT3 and GT4 energi'zesfvthemut motor 52 through wires 233;; 239- and- 2-40 l connected` withwthe power lines 1212--, 22 |.,and 222,. respectively.

Theicut-rnotor 52 Y positionedl at. the-top of fthe; apparatus, is therefore 'placed in operation, thence by-frotatingvthe shafts 6`3-for the .operational` units-fv VThis does not, however; resulty in .any movement of .the 1 workheads or rotation: of the toolfspindlesM 32, since the` clutches y. 1 I f are: all

disengaged due.' to the application-off thefluid.-

pressure Itothe cylinders, 83;- the` solenoids.-.con trollin'grthese valves vbeing deenergizedl at` this` time; 1

The operator nextfmomentarily actuatessw-itchxV |6&:1` This-'completes a` circuit from: thewirey 234V through the normally .closedfswitchfl 66;' the nowv close'dvV switch: 65; andf the coil ofal'relay P, the circuit beingi completed `to.`j the wire 230.1 Relay Pxisstherefore energized; closing: its normallyf open-l contacts P I3; P2;l P3 and" P41; l Closingfxthe.-con'-v tacts PI provides Ya holding: circuitfor: the-Irelay Pmaintaining the latter "energized whenz-the switch". |1|i5isireleased;` Closing. the contacts; -PZ' P'31and-P4 .energizesfthemotor i2-"fory thefcoolant; pump .throughi the' wires 24|; 242 andi 243`;'con'" :lecteur-respectively with the power fsupply lines: 220", 221 and'22.2. The.pumpirf'ortheacoolantfcon sequently.' vsupplies' this iliquid. through4 conduity |'52lafn'd pipe |53to the'reservoir' |54 intherturreti cap No coolant is, however; suppliedethrough thelnozzles I 56 'since'theivalves y| 511 fr'the Icoolant supply pipes I55`are now*Y closed'.y

During normal operation ofthe machineiun'der: automatic control, the turret: of the? machine: normally 'comesl to rest". as :each operational .unit is sequentially located at the loading station whereupon the completed workpiece isremoved and the workhead rapidlytraversedffto-its lower.;- Therefore, assuming that 1 an" operationaly unit 'is thus properly positionedf a'tth'e loading station and'its workhead isJat its 4upper."-vv most position, the .barA 201 'will' be engaged'lby the rodor actuator 2| Dasshown in Fig: 9'; thereby holding switch 205'? actuated so ythat fits-nor# 'mally closed contacts 205a`and v20'5Z5`are` openecl and normally open contact 205C is closedl The' switch 27| I willbe-in open position having-been actuated thereto by the former vupward'-movement of"'theewo1'kheadl SwitchV 212? will, however; be infclosed position since it is normally closed"v andf the-rod-or actuator 2I6 is' not Anowin engagement therewith.

The'closing of contact 205e completes la-rcir# cuit therethrough to' and throughtheindicating lamp towthel wire .230.1 The" resulting lightingiof lamp |12 indicates that an operational unit is properlypositioned at theloading station. Consequently, a momentary depression bor operation ofthe'push-'button` |69'fwill complete af circuit .rrA .ull

1.61* from the wire.2-34fthroughthenow vclosedcontactf- 205c,;throughithe normallyclosed'stop lswitchY |10,1: toithe switch, 60. This circuit continues throughe switch |B9and wires244aand24'5 tethefsolenoid.l

a. |46; for the V.valve |41- controlling shifting of `,the f driving:v gear -I32 -for -the-` rapid traverse mecha. nism'thecircuit being completedto the-w-ire-230.'` The coilf'of-a -timingf relay TA is-'connected-in.I parallel With-the-solenoid |46;V and isl-also` sirnul-.`

taneously energized.Y Energ-ization of the-sole#n noid |46=movesthevvalve |41 to operatedvposition therebyrpermitting -fluid under pressure ftofflowvf from the conduitfl 50 through the valve- I 41ffinteT the: inlet' ISS-for? the1',cylinder |33:- This: causese the-.pistonz rod 35 7"tor beI moved downwardly,l as. viewed inFig; 2B,: thusbrin'gingjthe gear* I 32-.err` the"rapid:tran'verse#mechanismintoengagementA wthtliegear |22-"on'th`e feedmut I9 of thefworkff head?" positionedfat the loading station. The downward "movement of the rodi @5f also causes' th'edisk v| 31 thereof-toengage thelever |42ttherefbyfremovi'ng the'pin I 45 'from between adjacent.4

teeth*ofthe'geanI'ZZ:v

The timing relayA TA, which was venergized-f simultaneouslywith the solenoid |48; is provided? to'close'a circuit controlling energization'of the rap-id1t'raverse`motor' |24" a predetermined timer after the valve |41 is operated. rThis.tim'edelay` is t'o insure thatthe pin |45f-hasbeen-properly withdrawnfromv4 between the teeth off the gea-r |22 and'that' the gears |32 `and"|22"are'properlw engaged before the motor' 24" is placed in roy tation. 'I'he operation of the cylinder`| 38is rela-f tively' rapidvv and hence .theitime delay interposed.' by; relay TA'is of relativelyshort duration'sanch the operatorV will maintain4 the,` push button: "SILF depressed throughout this time interval. When? the Acontact TAZ closes,'at"the1en'd iof.` this inten-ff va1,'a circuit iscompletedfrom wirez234throughf the push button switch" |60"and-wire246 toa wire 24T,- thence through the'Y closedffswitch 2|2';'1'ro51v;` closedi contactTAZ'V to and through; the coilloff. arelay RD; the circuit being completed' to'zthei wire 230; EnergizationY ofthe relay RD closesv itsnormally open'contacts RDI, RD2,"RD3, 155134?4 and RDSan'd'opens itsnorm'ally closed contacts RDS and RD1.' Closing of the-contacts'RDl 'an'd RDprovidesrholdi'ng circuits for thefrelay'- RD1 andforthe solenoid |46 and"relayTA, respe'c.A tively, thusl maintaining them energized afterI the push button ISS'is' released; Closing ofthe contacts RDZIRDS' and RD4 completes'ci'rcuits to themotor leads 243,'1'249 and`250 for the rapid! traverse motor |2`4` from the wire 25| 252- an'd` 25'3 which -arer respectively connected withthev power'lines 2 2 0; 22'I'and 222. As mentioned here--A tofore, the operator maintains the switch |69" depressed untilrelay RDis energized bythe de` layed closing of the contact TAZ. This interval.' is of relatively'shortduration andits terminat'ion is indicated by commencement of'operation ofthe rapid traverse lmotor |24. The energiza'- tion of relay TA' has Yalso closed ts'contacts' TAI' at the end of thevaforementioned time interval but Ano circuit is completed therethrough atf this time since contacts RD1 are open. Improper rotation'of the turret at this time cannot occur since' the contacts RDS are held open.'A

SinceV the clutch 1I is still deenergized, the' wormV |09 is stationary so that the feed screw IIB is prevented* from rotation. Hence,y the'V energization ofy therapid traverse motor |24 with resulting ldriving of gear |22 Yand rotation ofithe feed-'nut-'I |59 at a relatively rapid rateimoves the 17 f bered thatV the motor |24 vis energized through the contacts RD2, RD3 and RD4 in a direction which may be considered the reverse of its normal direction of rotation.

As the workhead moves downwardly, the rod or actuator 2 I5 thereon resets the switch 2 I I, movving its contact to closed position as indicated in broken lines in Fig. 12. This, however, completes no circuit at this time, since neither the Y switch |69 nor the contacts RUI are closed.

RDS, and RD4 deenergizes the rapid traverse Consequently, the valve I4'I for the motor |24. rapid traverse mechanism now moves back to its unoperated position, terminating the supply of fluid pressure to the cylinder |38 and placing the said cylinder in communication with the atmosphere. The spring |33 of the rapid traverse mechanism (see Fig. 2B) now moves the rod |35 upwardly disengaging the gear |32 from the gear IZZ and removing the disk I3'I from engagement with the lever |42, so that the pin I 45`may now drop between adjacent teeth of the gear |22 holding the latter from rotation. It will be apparent from the mechanism illustrated and described that there is little tendency for the gear |22 to coast after driving force is removed therefrom by deenergizing the motor |24 and that the gear |22 will be stationary or substantially so when the pin |45 drops between the teeththereof.

The workhead is now at its lowermost position at the loading station. The operator then places a new work blank or workpiece in the chuck onthe work spindle 40 and engages the tail stock 48 therewith through proper positioning of the tail slide 44. The operator then again depresses start switch |69 at the main control station and holds the latter depressed until the motor |24 begins operation. This operation of the switch |69 closes a circuit from the wire 234 through the still closed contact 205e of the switch 265, switch I'III'and the now closed switch |69, to the wires 244, 245 connected with the timing relay TA and the solenoid |46, the circuit being completed to the wire 230 as previously described. Now, however, the switch 2|2 is open and the switch ZII is closed. Therefore, although the solenoid |46 is energized operating the valve |41 for eiecting engagement of the rapid traverse mechanism with the workhead feed nut as previously described, relay RDA is not energized when the contact TAZ is subsequently closed. Instead, relay RU is now energized by the closing of the contact TAI, which is operated by the relay TA simultaneously with the contacts TA2. This circuit for the relay RU extends from the wire 234 through the closed contact 205C, switch |10, the now closed switch |69, closed switch 2| I, and the now closed contact TAI to and through the relay coil RU to the wire 236. The energization of the relay RU closes its normally open contacts RUI, RUZ, RU3, RU4, and RUG and opens its normally closed contacts RU5. Closing of the contacts RUI provides a holding circuit for relay RU about' the start switch |69 so that the latter may now be released. Closing of these contacts RUB provides a holding circuit for the relay TAl and the solenoid |46 maintaining these energized when the switch |69 is released. Closing of the contacts RUZ, RU3 and RUII now energizes the rapid traverse motor |24 for rotation in a forward direction since the motor leads 248, 249 and 250 are now connected respectively with the power leads 252, 25| and 253. The opening of the contacts RU5 has interrupted a circuit to the controls for the indexing motor 25 thus preventing inadvertent operation of the latter.

It will be apparent therefore, that the workhead will now move upwardly at its rapid traverse rate bringing the workpiece closely adjacent the tool or hob carried on the spindle 32.v When this position is reached the rod or actuator 2|5 will engage and operate the switch 2I| from its broken line position as shown in Fig. 12 to its open position as shown in full lines in the same figure. This opening of the switch 2|| deenergizes relay RU thereby causing it to open its contacts RUI, RUZ, RU3, RU4 and RU6 and closes its contacts RU5. Opening the contacts RUI and RUB opens the previous holding circuit for the relay RU, TA and the solenoid |46. Consequently, the valve I4`| is now positioned so that the fluid pressure is no longer suppliedlto cylinder |38, the latter being connected to atmosphere at this time with the result that the spring |33 disengages the rapid traverse driving mechanism as previously described, the motor |26 now being stationary since the contacts RUZ, RUB and RU4 have opened the energizing circuit for this motor. Also, the pin |45 is again positioned between adjacent teeth of gear IZZ.

During the upward movement of the work-l head, as just described, and at about the time switch 2|I is actuated, the. cam Z|8 has engaged switch 2I'I closing the latter. This cam is preferably of sufficient length to provide for some movement of the workhead vertically without disengagement of the cam from the switch. The

, initial closing of the switch lZ I 'I does not immediately eiect anyoperation since, as long as the switch 2| I is closed and the RU relay is energized with resulting energization of the rapid traverse lmotor |24, the circuit through the switch 2I`| is open at the RUB relay. However, when .the switch 2| I has been operated to open position, as previously mentioned, with the resulting deenergization of the RU relay, the RUE contacts now close. This completes a circuit from the wire 234 through the normally closed contacts RUS, RD5, switch |68, the initially closed switch the now closed switch ZI'I and through the normally closed switch 264, jog switches 254 and 255, to and through the relay ICR, the circuit being completed therefrom directly to the wire 236. This energizes the relay ICR closing its normally open contacts ICRI and ICRZ. Closing of the contacts ICRI provides a holding circuit about the switch 2|'I thereby maintaining the relay ICR energized when the rotation of the turret disengages the cam 2I8 from the switch ZII. Closing of contacts ICRI and ICRZ completes a circuit through the relay coil IL to the wire 236 thereby energizing this relay and causing it vto close its normally open contacts ILI, ILZ, ILS. Closing of these latter contacts completes a circuit to the index motor leads 256, 251 and 258 from the wires 259, 260, 26| connected, respectively, with the power supply lines 220, 22| and ZZ'Z. Closing of the contacts ILI and ILZ has 19 also energized the solenoid28 for the brake on the index motor 25. Therefore, the index motor 25 is energized and freed for rotation in a direction productive of rotation of the turret as indicated by the arrow R in Fig. 1.

As the turret begins to rotate the switch actuator ZIE moves from engagement withthe switch 295 thereby causing the latter'to open its contact 285e and close is contacts 205e and 2051). Opening of the contact 285C extinguishes the light |12 thereby indicating that a workhead is no longer positioned at the loading station. Shortly after rotation of the turret begins, the cam |94 on the bar ISE engages and operates the switch |9| provided on the back of the operational unit which is then leaving the loading station. Since the selector switch |528 was previously placed in its automatic position, the circuit is then closed through relay ECR and solenoids 88 and CS. This circuit extends from the wire 234 through the normally closed contacts '25,13% closed switch |89, the normally closed contacts 262a of the switch 282, associated with the hob shift mechanism in the housing I5I, to and through the now closed switch ISI, the closed switch |98, the normally closed switch |96 and the relay 2CR. to the wire 231. Parallel Vcircuits through the solenoids 88 and CS are also closed, switch |81 of the unit having previously been closed by the operator.

The relay ZCR, solenoids 88 and CS are maintained energized after the turret rotation has moved the cam |94 from operating engagement with the switch ISI, with consequent opening of the latter, since the circuit is maintained through the now closed contacts ZCRI of relay ECR. Energization of the solenoid 88 causes the latter to move the associated va-lve 86 to a position such that supply of iluid pressure to the cylinder 83 is discontinued and the latter is vented. rThis allows the clutch 1i of the unit to engage by virtue of the force exerted by the springs 16, so that the rotating shaft 63 is now connected through the clutch and rotates the shaft 1e. This causes rotation of the gears 89 and 93 which in turn rotate the gears 91 and Il. Rotation of the gear I!) drives the mechanism within the housing |5| thereby causing rotation and slow axial shift of the hob or tool carried upon the spindle 32. Rotation of the gear 81 causes rotation of the shaft 98 and the latter drives the gear |83, shaft |84 and gear train |38, worm |99 and worm wheel IID, thus rotating the Work spindle 48. Rotation of the work spindle, in turn, causes the gear to drive the gear ||5 through the gears |52 `and ||4. This rotates the feed screw H5 elevating the workhead at the feeding rate since the feed nut 9 is now held stationary'due to the engagement of the pin |45 between the teeth of the gear |22 connected with the feed nut of the unit. Since the hob or other tool is now in rotation and the work is rotated and moved vertically at the feeding rate, a hobbing or other machining operation is performed upon the workpiece of the operational unit. Coolant or cutting fluid is supplied to the hob and work during the hobbing operation since the energization of the solenoid CS has operated the valve |51 in the conduit |55 thereby allowing the flow of coolant vfrom ther reservoir |54.

The hobbing or other machining operation continues independently of rotation or non-rotation of the turret until the Aworkhead has moved upwardly a distance corresponding to completion of the machining operation. This causes the illuminated indica-ting 20 button or ,abutmentV |99 on the upper portion of the workhead to engage` the switch arm Y| 91 moving vthe switch ISS to open position thereby ldeenergizing relay BCR and solenoids 88 and CS. Deenergization of relay 2CR breaks the holding circuit through the contacts 2CRi and the deenergization of the solenoid CS terminates the supply of coolantV to the hob and workpiece.` Deenergization of relay 88 causes `the valve 86 to return to its Vposition in which fluid pressure is supplied therethrough to the cylinder 83 thereby disengaging 'the clutch 1| terminating rotation of ythe tool spindle 32, work spindle 48, and the feeding movement of the 'workhead through termination cf the rotation of the feed screw IS.

While the operational unit which has just been described as havingvbeen placed in operationis being carried by the turret from the loading station vand is effectingv the hobbing or other machining operation, a new operational unit is being moved into theloading station by rotation of the turret.V As this new operational unit comes to the proper position, 'the rod or switch actuator 2|'8 thereof Yengages the switch 2t4 opening the latter. This breaks the circuit to the relay ICR which it will be remembered Iwas held energized through the holding contacts ICRI. The 'resulting deenergization of the relay ICR causes it to open its contacts ICRI and |CR2.v This results in de'energization of 4the relay IL with resulting opening of the contacts ILI, ILZ and ILS. Opening of the latter contacts deenergizes the index motor 25 and the brake solenoid 28, thus termi; nating rotation of the worm 21 and the worm wheel 23. Due to the massiveness of the turret and the operational Aunits associated therewith, the turret will coast Vonly the very short distance so that the switch actuator moves from the bar 285 of switch 226i and comes to rest in engagement with bar 261 of switch 205. This distance may be predetermined' and the switch operating bars 208, 281 correspondingly positioned since it will be remembered these bars Vare adjustably mounted.

When the turret comes to rest, as above inentioned, the switch rod or actuator 2!!! remains in engagement with the bar 201 for the Switch 285 thereby closing :the contact 295e thereof and opening the contacts 295:1 and 25b. Closing the contact Zil'ic completes a circuit therethrough to and through the light |12 tothe wire 238. The light |12 is therefore illuminated indicating that an operational unit is again properly positioned at the loading station. In the normal operation of the machine the hobbingoperation performed by each unit will have been completed before that operational unit returns to the loading station. If, however, the machining or hobbing operation has not been completed the operator will readily observe this by the fact that the workpiece and the tool are still in operation and hence will not operate the rapid ltraverseY start motor push button |69. Instead he will simply allow the machine to stand without rotation of the turret until the hobbing operation of the unit positioned at the loading station is completed and the switch I Se thereof thus operated to open the circuit disengaging the clutch 1i. As noted above, however, it is generally not necessary to Wait since the bobbingV operation 'will beY completed by the time the operational unit has returned to the loading station and the operator can then actuate the push button |69 asY soon as the light |12 is that the unit, is in proper position.

Actuation of the push button switch |69 again completes the circuits, p-reviouslyV described, extending through the wires 244, 245, relay TA and solenoid |46, in parallel to the wire 230. This energizes the valve |47 operating the rapid traverse mechanism to engage the gear |32 thereof with the gear |22. Likewise, the rapid traverse motor I 24 is again energized as has been previously described. The workhead of the newly positioned operational unit is, therefore, rapid traversed back to its initial position during which movement the switch 2 II is reset, the movement being terminated when the workhead has reached its lowermost position and opened the switch2l2. A new workpiece may then be placed in this unit and the operation thereof resumed, by again depressing the start button I 66 whereupon the workhead moves in the'upward direction at the rapid traverse rate until switch 2 I I is opened, the subsequent operations then continuing as previously described.

./-lsv mentioned heretofore and as is fully described in the aforementioned applications S. N. 757,256, filed January 25, 1947, and S. N. 56,726, filed October 27, 1948, the hob or tool spindle 32 is axially shifted at a very slow rate while it is being rotated, this continuous shifting being for the purpose of evenly distributing the wear upon the hob or other tool thereby increasing the life of the hob. When the hob spindle 32 has thus shifted its maximum extent and the hob must be replaced or reground, mechanism of the type disclosed in the said applications operates the switch 262 within the housing thereby closing the contact 262D and opening the Contact 262e of that switch. Closing of the contact 2525 lights the lamp |86 provided on the unit switch assembly V|85 for that operational unit thereby indicating that the hob or other tool of the unit must be replaced. Opening of the contacts 262e does not terminate the hobbing or othermachining operation then in progress by the unit since a holding circuit is provided about the contact 26211 by the contacts ZCRI of the relay 2CR. However, when the machining operation has been completed and the switch |96 has therefore been operated, as previously described, to its open position a new hobbing operation cannot again be initiated for that operational unit even though the switch ISI- be closed by rotation of the unit past the stationary cam |94. This follows from the fact that the contact 252er is now open so that the circuit for energizing the relay 2CR, solenoid 88 and solenoid CS-cannot be completed. The operational unit may, however, be restored to operaty.. ing condition by returning the spindle 32 to its initial position, after having replaced the hob or other tool. This will result in opening of the contact 252e and closing of the contact 2521 of the microswitch 252.

In the event that any of the operational units overtravel, that is, if the work-head of any unit the coil of the relay SR, t-he collector ring |14.'

brush |19, wire 235 and the now closed contact 203b to the wire 263, and thence to wire 231, brush |8I, and collector ring |16 to the wire 230. This energizes the relay SR causing it to open its contacts SRI, thereby breaking the circuit between the wires 233 and 234 so that the entire control circuit for the machine is deenergized terminating operation of all motors of the apparatus.

Manual operation Theapparatus of this invention is also adapted for manual operation as Well as automatic oper-- ation. Such manual operation is, of course, ad-

vantageous during initial set up and when making'.

repairs or adjustments to the machine. In order to effect such manual operation the switch |1| at the main control panel or box ISI is moved to its manual position and the toggle switches |902 at each of the separate operational unit control boxes is moved to the manual position. The apparatus is placed in operation, as'before, by' closing the switch 223, and by applying air pressure to the conduit |49, thus closing the switch |50. The operator then pushes the start button |63 for the cut motor 52 and start button |65 for the coolant pump motor |62 thus placing these motors in operation as will now be readily apparent.

' Under manual operation the machine has normally not been previously set up and therefore the turret may not be located so that an operational unit is positionedl exactlyat the loading station. `Assuming that the turret is notthus properly positioned, this positioning may be effected by inching or jogging the index motor 25 to rotate in one or the other directions as may be necessary to bring the turret to proper position. If the turret stands at a position such thatv rotation in the direction designated R would result in proper positioning, rotation of the turret may be eiected by pressing the start switch |67v for the index motor 25 which will thus energize the relay ICR closing its contact ICRI and |CR2 thereby energizing relay IL. Energization of the relay IL closes its contacts ILI, IL2 and IL3 thus energizing the index motor 25 for rotation tothe left as viewed in Fig. 1 which is its normal direction of travel, the solenoid 28 also being energized so that the brake is released. The turret will then rotate and come to rest through operation of switches 204 and 205 as previously described vunder automatic operation.

In the event the turret has already operated too far in they direction R, rotation may be terminated and rotation in the opposite direction effected by actuating the jog button 255. Since the turret will have been too far beyond its proper position, the switch 205 will not be held engaged and consequently the contacts 2050i and 255i) thereof will be closed. Therefore `operating the jog button 255 will now close a circuit through the normally closed contacts RU5, RDS, switch |68, wire 264, to and through the contact 205b and the lower contact 2551) of jog switch 255, the circuit being completed through the relay IR to the wire 230. Relay IR is therefore energized and simultaneously therewith the relay ICR is deenergized since the circuit therethrough has been opened at the ,contact 255a of the jog switch` This deenergization of the relay ICR has also deenergized rela-y IL since the contactsY |CR| and |.CR2 are now open. Therefore, the motor 25 is no longer energized through the contacts ILE, IL2. and IL3 but is now energized through the contact IRI, |R2 and |R3 so that the power lines 259,` 266 and 26| are now respectively connected with the motor leads 251, 256 and 258. Therefore the brake 28 is now released and the motor 25 is energized for rotation in its reverse direction. This will continue as long as the jog switch 255 is held depressed and will terminate as soon as that switch is released as will be apparent from Fig. 12. The instant when the turret is properly positioned will be indicated by lighting of the indicating lamp |12 as the result of actuation of switch 265 by the switch operator 2 |61.

If the turret should coast beyond its proper position the light |12 will be extinguished and the turret may be returned to its proper position by then operating the jog switch 254. Actuatio-n of this switch closes a circuit through its lower contact 25412 from the wire 264 through the normally closed contact 265e, now closed contact 254D to and through the relay IL, the circuit being completed to the wire 236. Hence the relay IL is now operated only so long as the switch 254 is held engaged since its upper contact 254:1 has opened the circuit to the holding relay iCR. As heretofore mentioned, energization of the IL relay closes the circuit from motor 25 through the contacts ILI, IL2 and IL3 causing rotation of the turret in the direction R as indicated by the arrow in Fig. 1. Hence by repeated operation the jog switches 254 and 255, the turret may be properly positioned with one of the operational units thereof at the loading station, thereby engaging the switch 265 soY that the contacts 255e, 2051)- thereof are open preventing further jogging operations while the switch 285e is closed illuminating the lamp |12 and indicating that operations may now be performed by the unit thus positioned at the loading station.

The push button switch |69 of the operational unit at the loading station is now actuated. This closes a circuit from wire 234 through the now closed contact 205e, switch |69, wire 244, wire 245, to and through the relay TA and the solenoid |46 in parallel thence to the wire 230 thereby energizing solenoid |46 and the relay TA. Energization of the solenoid |46 moves the rapid traversing mechanism to engage the gear |32 with the gear |22 of the operational unit and release the pin |45 from between the teeth of the gear |22 while energization of relay TA closes its contacts TAI and TAZ a predetermined time thereafter as previously described.

Due to the nature of the switches 2|| and 2 |2, if the workhead be not at its lowermost position, the switch 2 l2 will be closed. Consequently upon actuation of switch |69, when the workhead is at any position other than its lowermost position, a circuit is completed through the said switch |69, wire 245, wire 241, switch 2 l2, the now closed contact TA2 and the relay RD, the circuit being completed through the latter to the wire 23. Energization of relay RD closes its contacts RD RD2, RD3, RD4 and RDS and opens its contacts RD5 and RD1. Consequently, the rapid traverse motor |24 will be energized in a direction to return the Workhead to its initial lowermost position in the manner previously described, a holding circuit for the relay RD being provided by contacts RDI While the holding circuit for the relay TA and solenoid |46 is provided by the contacts RDS. When the workhead has reached its lowermost position, contact 2|2 is opened thus deenergizing relay RD, thereby terminating rotation of the rapid traverse motor |24 and deenergizing the solenoid |46 with resulting exhausting of fluid pressure from the cylinder |38 of rapid traverse mechanism so that the gear |32 is now disengaged from the gear |22 by action of the spring |33.

The workpiece may now be inserted in the operational unit positioned at the loadingstation of the apparatus and the push button 69 again actuated. Since the workhead is now at its lowermost position, Ythe switch 2|? will be open and the switch 2|| will be in closed position. Hence a circuit is now completed through the switch |69, wires 244 and 245 energizing the relay TA and the solenoid Hit/with the result that the contacts TA| and TA2 are closed a predetermined time after actuation of the valve |41 supplying fluid pressure to the cylinder |38, as before described. Hence, the rapid-traverse drive is again connected with the gear |22 of the operational unit and a circuit is now completed through the still depressed switch |69, the sWitchZll, the contact TA| to and through the relay RU, the circuit being completed from the latter to the wire 230. Therefore, the'RUrelay is now energized, closing its contacts RUI, RUZ, RU3, RU4 and R116 and opening its contacts RU5. Contacts RUI provide a holding circuit for the RU relay while the contactsV RUS provide a holding circuit for the TA relay and solenoid |46, thereby insuring that the rapid traversing mechanism remains in engagement `with the gear |22. The closing of the contacts RUZ, RU3, RU4 energizes the motor. |24 for rotation ina direction effecting rapid traverse movement of the workhead in the upward direction which continues until the pin or actuator 2|5 engages switch 2| to move its contact to open position thereby breaking the circuit through the RU relay deenergizing the latter and `hence the rapid traverse motor as well as eifecting disengagement of the rapid traverse mechanism from the gear |22 as previously described.

The workhead with the workpiece therein has now been rapid traversed to a position such that the workpiece is adjacent the hob or tool on the Spindle 32 and the feed nut is now held from rotation by virtue of the pin |45 being between adjacent teeth of the gear |22. The operator now momentarily depresses the Ystart button |88 at the unit control box for the unit which is positioned at the loading station. This completes a circuit from the wire 236 through the contact 23a, switch |69, contact 262a, switch |88, switch |96 to and through the relay 2CR, the circuit being completed at the wire 238. Likewise, the solenoid 88, controlling the valve 86 for the clutch 1| of the unit, and the CS solenoid, controlling the valve |51 for the coolant of the unit, are energized in parallel with the relay 2CR, the switch |81 for the coolant having been previously closed by the operator at the unitstation |85. Energization of Vrelay 2CR provides a holding circuit about the switch |88 by closing of contact 2CR| so that the relay 2CR, solenoid 88, and Vsolenoid CS remain energized after the push button |88 is released. Y

The energization of relay 88 has moved the valve 86 thereof to thereby terminate supplying fluid pressure to the cylinder .83 with the result that the clutch 1| for the unit is engaged, consequently rotating the tool spindle 32, work spindle 40 and thefeed screw ||6 as has been previously described. Therefore the workhead is now piece. `moved vertically to a position such that the butvton-or abutment |99 engages and operates switch brake 2a. 'A however, will coast aslight distance and this distance is just sufficient to bring the arm or actumoved at a feeding rate bringing the workpiece into engagement with the tool and the machining operation-is therefore performed on the work- This continues until the workhead has |96 thus opening the 'circuit for the relay ZCR, solenoid 88 and solenoid CS. Deenergization of relay 2CR breaks the holding circuit for this relay and the solencids 8B and CS. The deenergization of solenoid 88 again eiiects disengagement of the clutch Il and ,deenergizationfof solenoid CS terminates the supply of coolant to the workpiece so that the machining operation is terminated.

f, The machined workpiece may then be removed position of its downward movement the switch. 2,12 is'opened terminating the movement; A new workpiece may then be inserted andthe appa- Vratus again utilized for machining by employing the same operational unit which is still located -at the ,loading station. Hence the machine may beoperated as a single unit mechanism although normally this type of manual control is intended for use only in setup of the device.

When it is'desired to utilize another operational unit of the mechanism, the turret may be indexed as previously described by depressing start buttonjll. Since the operational unit which has been performingthe y. machining operation was accurately located at the loading station, it will bev apparent that the switch 204 will be closed. Hence the relay ICR Will be energized, thereby closing its vcontacts lCRl, ECRZ with resulting energization Vof relay IL. The latter relay then closes its contacts ILI, IL2 and ILB energizing the index motor 25 and the brake 28 so that the motor now moves the turret in the direction indicated by the arrow in Fig. l. This movement 'continues until the now operational unit is substantially positioned Vat the loading station at which time the arm or actuator 2m engages switch 204 momentarily opening the latter and deenergizing relay ICR. This opens contacts ICRI, ICRZ, deenergizing the relay IL thereby deenergizing the index motor 25 and applying the As mentioned heretofore, the turret,

ator 2I0 into engagement with the switch 205 closing the latter as is indicated by illumination of the light H2. In the event the turret Should haveoverrun, it may be returned to its proper position by suitable jogging operations employing the buttons 254 and 255 as previously described. The new operational' unit may then be set up and employed in a machining operationV as was previously described above and these operations of indexing and settingV up of each unit are repeated until 'each unit `has been properly adjusted. The machine may then be placed in automatic operation as previouslydescribed.

SUMMARY i It must be apparent'that the new and fimtype but nevertheless employs only a single rapid traverse motor for effecting a power driven rapid traverse movement ofthe individual workheads mounted upon the turret, yThis is effected by mechanism which provides for accurate positioning4 of each operational unit for cooperation with vthe rapid traverse mechanism. The machine Yother features of operationoften employed. It

will be apparent, however,y that by the use of suitable additional controls such, for example, as

'those illustrated in my` copending application 757,256, the machine Imay be adapted for performing operations in addition to those here specifically set forth.

While the several switches mounted upon the stationary portion ofthe apparatus for operation by each workhead as the latter is positioned at the f loading station have been indicated as mounted upon the apronor skirt for cooperation with abutments or actuators on the lower part of the Workhead, it will be apparent :that the switches and actuators'm'ay be otherwise positioned. For example', the .switches might be provided upon a stationary ring surrounding the upper' portion of the apparatus for cooperation with actuators carried upon the upper parts of the workhead. Moreover, it will be apparent that provision will be ordinarily made for adjusting the positions of the several cams or switch operators such as 2li), 2|5, 216 and 2I8 on the workhead as well-as for the adjustment of the switches 2li, 2I2,y 2H, 204, 205 as shown.

Moreover, althoughthe invention has been described as embodied in a machine for performing hobbing operations, it Will be apparent that the invention is not limited thereto but may be embodied in machine tools for performing other operations by the substitution of suitable tools and (actuating mechanisms for .the hob. Other variations and changes, in addition to those specifically mentioned above, may be likewise made by those'skilled in the art and therefore, while the preferred embodiment has been described in considerableY detail, it is to be understood that the invention is not conned to the particular constructions illustrated and described means automatically terminating rotation of the Yturretv as each unit is sequentially positioned at a ysingle loading station, and rotation producing means mounted on said base and sequentially operatively engaged with one of said relatively rotatable members of each unit when the latter is positioned at said loading station to effect movement of said slidable member of that unit. L 

